Assessment of indoor air quality and their inter-association in hospitals of northern India—a cross-sectional study

This study was commenced to evaluate the indoor and outdoor air quality concentrations of PM2.5, sub-micron particles (PM>2.5, PM1.0–2.5, PM0.50 –1.0, PM0.25–0.50, and PM<0.25), heavy metals, and microbial contaminants along with their identification in three different hospitals of Lucknow City. The study was conducted from February 2022 to April 2022 in hospitals situated in the commercial, residential, and industrial belts of the city. The indoor concentration trend of particulate matter as observed during the study suggested that most of the highest concentrations belonged to the hospital situated in an industrial area. The highest obtained indoor and outdoor concentrations for PM1.0–2.5, PM0.50–1.0, PM0.25–0.50, and PM<0.25 are 40.44 µg/m3, 56.08 µg/m3, 67.20 µg/m3, 74.50 µg/m3, 61.9 µg/m3, 79.3 µg/m3, 82.0 µg/m3, and 93.9 µg/m3, respectively, which belonged to hospital C situated in the industrial belt. However, for PM>2.5, the highest indoor concentration obtained belonged to hospital B, i.e., 30.7 µg/m3, which is situated in the residential belt of the city. Regarding PM2.5, the highest indoor and outdoor concentrations obtained are 149.41 µg/m3 and 227.45 µg/m3, which were recorded at hospital A and hospital C, respectively. The present study also observed that a high bacterial load of 1389.21 CFU/m3 is recorded in hospital B, and the fungi load was highest in hospital C with 786.34 CFU/m3. Henceforth, the present study offers thorough information on the various air pollutants in a crucial indoor setting, which will further aid the researchers in the field to identify and mitigate the same more precisely.